Three-Dimensional Arterial Anatomy of the Gluteus Maximus and the Proper Method of Muscle Splitting

Abstract

Sir: The gluteus maximus muscle is a large muscle that is sometimes used as a split muscle flap in reconstructive surgery. Although several methods have been reported for splitting the gluteus maximus muscle,1–4 the proper method based on three-dimensional arterial anatomy has never been described. Using fresh cadavers, we performed systemic angiography. After dissecting the gluteus maximus muscle from the surrounding tissue, stereoscopic images were taken, and the three-dimensional arterial anatomy was reviewed (Fig. 1). Cadaveric studies demonstrated that the peripheral arteries inside the muscle are oriented in the direction of the muscle fibers, and the lower gluteal artery and the first perforating artery are strongly connected. From these observations, three methods can be used. The first is a superior gluteal artery pedicled flap using the superficial half of the gluteus maximus muscle where the skin is situated in the distal portion. The second is an inferior gluteal artery pedicled flap using the superficial half of the gluteus maximus muscle where the skin is situated in the distal portion. The third is a first perforating artery pedicled flap using the superficial half of the gluteus maximus muscle where the skin is situated medially. In all cases, the deeper part of the gluteus maximus muscle is preserved. Because the perforating branches in the muscle are difficult to identify, dissection of the muscle for the splitting should be performed with one-fifth of the muscle length around the pedicle untouched. Six patients with a total of seven skin defects underwent reconstruction with a split gluteus maximus musculocutaneous flap. In all cases, the flaps took well without any evidence of necrosis. The profiles of patients and results are listed in Table 1. A representative case (case 4) is shown in Figures 2 and 3. The application of the type of split gluteus maximus musculocutaneous flap depends on the sites of the skin defect. From our experience, the superior gluteal artery–based split gluteus maximus musculocutaneous flap is suitable for reconstructing the sacral and sciatic areas, the inferior gluteal artery–based split gluteus maximus musculocutaneous flap sciatic area, and the first perforating artery–based split gluteus maximus musculocutaneous flap greater trochanter area. The merits of using a split gluteus maximus muscle flap are as follows: (1) it is easy to perform; (2) there is less dead space and serous discharge from the drain becomes less after surgery; (3) the part of the function of the gluteus maximus is preserved; and (4) compared with the “perforator flap,” the surgeon does not need to worry about disturbing important perforating arteries. In contrast, the limits on how thin the muscle can be or how small the pedicle can be have not been delineated from the anatomical data. From our clinical cases, construction of a gluteus maximus musculocutaneous flap using half of the gluteus maximus muscle thickness with four-fifths of the muscle being dissected free was performed safely.Fig. 1.: A stereoscopic view of the gluteus maximus muscle demonstrates that the upper half of the gluteus maximus muscle is nourished by the superior gluteal artery (yellow arrow), and the lower half is nourished by the inferior gluteal artery (red arrow). The lateral portion is nourished by the first perforating artery of the deep femoral artery (blue arrow). Peripheral branches are inclined to the direction of the muscle fiber. The peripheral areas of the inferior gluteal artery and the first perforating artery communicate with one another (dotted line).Table 1: Profiles of the Patients and Clinical Results of the Split Gluteus Maximus Musculocutaneous FlapFig. 2.: A 40-year-old man with hidradenitis suppurativa on the right buttock underwent a split gluteus maximus musculocutaneous flap reconstruction based on the distribution of the superior gluteal artery (left). The dissection was performed at 50 percent thickness of the gluteus maximus, and three-fourths of the full length of the muscle was used (right).Fig. 3.: The patient immediately postoperatively.In conclusion, the gluteus maximus muscle can be safely split along the superficial and deep layers of its muscle fibers based on its blood supply. This technique represents an easier and safer method for reconstructing defects found in the gluteal region. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. Kazuo Kishi, M.D., Ph.D. Hideo Nakajima, M.D., Ph.D. Department of Plastic and Reconstructive Surgery Nobuaki Imanishi, M.D., Ph.D. Department of Anatomy Tatsuo Nakajima, M.D., Ph.D. Department of Plastic and Reconstructive Surgery Keio University School of Medicine Tokyo, Japan